# Diattenuation of Brain Tissue and its Impact on 3D Polarized Light Imaging

## TL;DR

This paper investigates diattenuation in brain tissue and finds it has minimal impact on fiber orientation measurements in 3D-Polarized Light Imaging but can reveal additional anatomical details, suggesting a new imaging extension.

## Contribution

It provides a comprehensive analysis of diattenuation in brain tissue and demonstrates its potential as an additional imaging contrast in neuroanatomy.

## Key findings

- Diattenuation in rat brain tissue is below 4%.
- Diattenuation has negligible effect on fiber orientation in 3D-PLI.
- Diattenuation imaging can reveal anatomical structures not visible with current techniques.

## Abstract

3D-Polarized Light Imaging (3D-PLI) reconstructs nerve fibers in histological brain sections by measuring their birefringence. This study investigates another effect caused by the optical anisotropy of brain tissue - diattenuation. Based on numerical and experimental studies and a complete analytical description of the optical system, the diattenuation was determined to be below 4 % in rat brain tissue. It was demonstrated that the diattenuation effect has negligible impact on the fiber orientations derived by 3D-PLI. The diattenuation signal, however, was found to highlight different anatomical structures that cannot be distinguished with current imaging techniques, which makes Diattenuation Imaging a promising extension to 3D-PLI.